Controlled dosage syringe



P 1960 G. N. HEIN, JR 2,952,255

- CONTROLLED DOSAGE smmcs Filed Nov. 25. 1956 2 Sheets-Sheet 1INVEIIQTOR ATTORNEY Sept. 13," 1960 s. N. HEIN, JR

CONTROLLED DOSAGE SYRINGE 2' Sheets-Sheet 2 Filed Nov. 23, 1956 "A m 1 2a 7 6% [L Z l L ll- KL M 2 My m I i H M m J 2 f 5 Km, Km

ATTORNEYS United States Patent ()fiice 2,952,255 Patented Sept. 13, 19602,952,255 CONTROLLED DOSAGE SYRINGE George N. Hein, Jr., San Carlos,

ton, Dickinson and Company, poration of New Jersey Calif., assignor toBec- Rutherford, NJ., a cor- This invention relates to a structurallyand functionally improved syringe of the controlled dosage type.

By means of the present teachings an assembly is furnished which mayreadily be combined with a syringe of proper design to furnish amechanism capable of being easily and rapidly operated termined amountsof fluid and in which a compact grouping of the mechanism will beeffected.

Moreover by means of the present invention, the parts of the assemblymay be'readily set to provide for a desired volumetric capacity and maybe operated through a series of cycles with assurance that this capacitywill be maintained.

Among additional objects are those of providing an assembly involvingsterile syringe components which can easily be grouped together withother required parts of a non-sterile nature without contamination ofthe syringe resulting. Additionally, the assembly may be economicallyprovided and will be extremely compact and of light weight; the dosagebeing readily set-up and the apparatus being capable of operationwithout any especially skilled technique being necessary.

With these and other objects in mind, reference is had to the attachedsheets of tical embodiment of the invention and in which:

Fig. l is a fragmentary side elevation of a complete assembly of whichthe syringe may form in part;

Fig. 2 is a partly sectional edge view of the syringe in process ofassembly;

Fig. 3 is a plan view of that syringe.

Fig. 4 is a sectional side view taken along the line 4-4 in thedirection of the arrows as indicated in Fig. 3;

Fig. 5 is a view similar to Fig. 4 but showing the parts in a slightlydifferent position;

Fig. 6 is a transverse sectional view taken along the line 66 in thedirection of the arrows as indicated in Fig. 5; and

Fig. 7 is a fragmentary end view of the syringe assembly.

Referring primarily to Figs. 2 to 5 inclusive, the numeral 10 indicatesthe barrel of the syringe. The latter in accordance with conventionalpractice is provided with end defined by an outwardly extending flangeThe opposite end of the barrel presents an end wall from which a boredtip 12 extends. The latter is preferably tapered to provide a Luer typecoupling to for example-engage the bore or inner surface of a hub orcorresponding unit. Adjacent tip 12 the syringe may mount a fitting 13also preferably of conventional type as part of a coupling structure.Reciprocal within the bore of barrel 10 is a plunger 15. The length ofthe latter is such that it may extend from a point in contact with theinner face of the end wall of the barrel to a point beyond the flangedend 11 of the latter. It terminates in an actuating portion 16. Both theplunger and syringe barrel are preferably formed of glass and the outerface of the barrel may present indicia 14, so that with the end of theplunger aligned therewith the to dispense precisely prede-v drawingsillustrating one prac-' volume between the end of that element and theend wall of the barrel will be known.

As part of theassembly, a collar 17 may be furnished, the internaldiameter of which corresponds to the exterior diameter of barrel 10.This collar is conveniently provided with an'outstanding flange portion18 adjacent one end. At its opposite end it is furnished with screwthreads which cooperate with threads formed in the inner face of a ring20 having its free edge extending inwardly. Thus, an overlapping edgezone forms a part of this ring, and defines a diameter less than thediameter of flange 11 which may be received between the same and theadjacent edge of collar 17. If it is desired to incorporate in theassembly, front finger supports, these may be furnished as at 19 andsecured to the flange portion 18 of collar 17.

Flange or extension 18 is provided with a transversely extending opening21 in a plane beyond ring 20. A bar extends through this opening andincludes oppositely flared portions 22 and 23. Secured to the end of thelatter is a cup shaped unit 24 of arcuate configuration and extendingthroughout a Zone such as has been shown in Fig. 7. This member providesa seat for actuator 16 and the edges defining its ends or slot areseparated for a distance at least equal to the diameter of plunger 15.Mounted upon the bar is a stop member 25 provided with the transverseopening of a diameter greater than the maximum width or thickness of thebar. This member supports the threaded shank of a stop screw 26. Thelatter has its end engageable with the adjacent bar surface which asespecially shown in Fig. 6 should be flat for cooperation therewith.

A spring assembly preferably involving a pair of resilient strips 27 isinterposed between collar 17 and cup 24. As shown, these springs are inthe form of fiat bowed strips disposed at diametrically opposite pointsin the assembly and conveniently having their ends secured in positionby screws or rivets. If finger supports, such as 19 are employed, theymay also retain the latter in position. The proportioning and setting ofthe parts is preferably such that when the actuator 16 is not associatedwith cup 24, the latter shifts to a position slightly non-aligned withthe bore of the barrel. This has been shown particularly in Figs. 2 and4, and also indicated in dot and dash lines in the latter figure.Accordingly, with the plunger 15 within the barrel bore, and theactuator in operative association with cup member 24, the latter isbiased so that the actuator will not be accidentally displaced withrespect to the cu However, when the actuator is once shifted in an axialdirection, so as to clear member 24, the parts will remain in nonalignedposition.

While an assembly of the type herein described may be combined withvarious forms of mechanism, it is especially useful when employed forexample as part of a grouping such as has been shown in Fig. 1. In thatview, it will be seen that there has been applied to the fitting and tipassembly of the syringe a casing 28 within which a pair of valves (notshown) are disposed. To the outer end of this casing the hub 29 of acannula 30 has been applied. A branch 31 extends from casing 28 andconnects with a tubing 32. To the outer end of the latter a sinker 33 isapplied. When suction is exerted, within the bore of tube 32, fluid willflow into casing 28 and so into the interior of syringe barrel 10. Nofluid will be drawn through the lumen of cannula 30 into the interior ofcasing 28. With pressure exerted within the casing, the valvesassociated with the latter will function to prevent a return flow offluid through branch 31, but will permit such flow from the tip of thesyringe barrel through the lumen of the cannula.

As is apparent, any number .of different groupings of parts might beapplied to the syringe. According to such association the assembly wouldbe of primary utility for one or another purpose. In connection withlaboratory work, the apparatus might be employed to transfer exactamount of liquid (suchas diluent material), and reagents to test tubes.The device might alsobe employed in the veterinary field and in thepharmacuetical and druggist professions Where it could be employed inlieu of a filling machine to repeatedly dispense predetermined amountsin exact volume into vials, ampules and other receptacles. Used simplywith a hypodermic needle, and free from the valve mechanism embracedwithin casing 28, injections might be achieved by blind diabetics withcertainty that an exact dosage would be dispensed.

In connection with all of such uses, and referring merely to the syringeassembly, it would be understood that with a barrel and plunger of thegeneral type described being available, the collar 17 may readily beapplied to the barrel. Now by mounting ring 20 upon the collar, theflanged end of the syringe would be fixed with respect to these parts.Cup member 24 is moved laterally so that its recess is aligned withactuator portion 16 and the latter is seated therein. This will retainmember 24 in association with the plunger. That unit is now projectedfrom, for example, the position shown in Fig. 4 to that illustrated inFig. 5. So projected, the end of the plunger will align with thatgraduation of indicia 14 which indicates the desired dosage to bedispensed. Under these circumstances, set screw 26 is loosened and stop25 is slid along bar portion 22 to a point where it abuts the flange orextended portion 18 of collar 17. Thereupon set screw 26 is tightened toengage against the surface of bar part 22. Under those circumstances itis apparent that plunger 15 may not be retracted with respect to thebarrel beyond a certain point determined by the elect-ed indicating mark14.

With conditions such as the foregoing prevailing, springs 27 willobviously have been placed under tension. They will constantly urgeplunger 15 to its extreme retracted position. Stop member 25 will nottend to move axially of the bar 2223 because of the wedge shapedstructure incorporated in the latter which-when set screw 26 has oncebeen tightenedwill prevent outward movement of the stop member along thebar. Therefore, an operator upon bringing pressure to bear againstactuator 16 will cause plunger 15 to be projected to a position incontact with or immediately adjacent the end wall of the syringe barrel10. Upon release of this pressure, plunger 15 will be retracted bysprings 27 so that the syringe will perform an aspirating function. Itis apparent that this cycle of projection and retraction may be quicklycompleted.

If it is desired to readjust the dose all that will be necessary will befor the operator to project the plunger to its full extent. Thereuponset screw 26 will be loosened and stop member 24 may be shifted tolightly bear against flange or extension 21. The setv screw is thencaused to lightly engage the bar. Now by grasping the barrel andgradually loosening the screw the springs 27 will smoothly and slowlyretract the plunger as the operator continues to loosen the set screw.When the plunger has retracted to a point where its inner end alignswith the desired graduation of the barrel, the set screw is fullytightened, and the new dosage volume will be established.

As will be understood, with apparatus of the present type, thediificulties inherent to earlier mechanisms are overcome. Moreparticularly, where these mechanisms employed a circular or helicalspring encircling the plunger or piston, theyv contacted the latterduring operation of the apparatus. This resulted in unnecessary frictionand frequently in a soilingof the side face of the piston. As will beunderstood, with the present apparatus, involving springs 27 which aremaintainedout of contact with the.piston,'no difiiculties inthisconnection will be p d.- or ve the overall len th of. the apparatus willbe materially decreased by the use of the present structure.

Thus among others the several objects of the invention as specificallyaforenoted are achieved. Obviously numerous changes in construction andrearrangements of the parts may be resorted to without departing fromthe spirit of the invention as defined by the claims,

I claim: 7

lfA syringe assembly including in combination a barrel having an openrear end, a plunger reciprocal within the bore of said barrel andextending beyond its end, an actuating portion at the outer end of saidplunger, a mounting supported by said barrel and extending exteriorlythereof, a spring means to one side and also exteriorly of said barrel,said spring means extending between said mounting and actuating portionto urge said plunger to a retracted position and stop means connectedwith said portion and mounting to limit the distance of retraction ofsaid plunger with respect to said barrel.

2. In a syringe assembly as defined in claim 1, said stop meansincluding a bar connected for movement with said portion and said barslidably engaging said mounting.

3. In a syringe assembly as defined element adjustably carried by saidbar and said element cooperating with said mounting means to limit themovement of the bar with respect thereto.

4. In a syringe assembly as defined in claim 3, said bar being wedgeshaped, said element having an opening through which said bar extendsand a set screw carried by said element to project toward the face ofsaid bar.

and to arrest sliding movement of the latter at a point in. its wedgeconfiguration corresponding to that at which. said screw Wedges againstits face.

5. In a syringe assembly as defined in claim 1, said spring meansembracing a strip outwardly bo wed with respect to said plunger, one endof said spring being connected to said mounting and supporting meansconnected to the opposite spring end to bear against said actuatingportion.

6. In a syringe assembly as defined in claim 1, supporting meansinterposed between said actuating portion and spring, and saidsupporting means tending to shift to an off-set position with respectto. the axis of said plunger.

7. In a syringe assembly as defined in claim 1-, the support betweensaid barrel and mounting comprising a, flange forming a part of theformer, andmeans at least partially enclosing said flange to retainsaid. mounting with respect to said barrel.

8. In a syringe assembly in combination abored barrel, aplunger-reciprocal within said bore and extending beyond the same, anactuating portion. forming a part of said plunger adjacent its outerend, a collar bearing againstsaid barrel, a pairof.outwardlybowedsprings at diametrically opposite .points in said assemblyand secured.

at one of their ends to said collar, means connecting the opposite endsof said sprlngs with said actuating portion..

and means extending between the latter and said'collar to limit theamount of plungereretraction with respect to said barrel.

9. Fornsewitha syringe assembly, amountingmemw ber to be disposedadjacent-to the open endofa syringe.

barrel, means to engage the actuating portion of a syringe plunger, apair of bowed'springs arranged in 0p-. posedrelationship and securedbetween saidlatter means.

and s aid mounting member and; stop means connecte to move with saidportion and also to engage and cooperate with said mounting member tolimit. the movement imparted by said spring to suchmeans.

in claim 2, a stop' said bar and engageable with said mounting and saidbar lying intermediate said pair of springs.

11. In an assembly as defined in claim 9, said mounting membercomprising separable elements and said elements furnishing at least apartial enclosure for a flange portion extending from the barrel of thesyringe.

12. In an assembly as defined in claim 10, said bar being wedge shapedand a set screw canied by said element and engageable with a surface ofsaid bar.

13. For use with a syringe assembly, in combination a mounting to besupported by the barrel of such an assembly, a support for engagementwith the actuating portion at the outer end of the plunger of saidassembly, a pair of outwardly bowed springs extending between saidmounting and support and stop means also extending between said mountingand support to limit the distance by which said elements may beseparated.

14 In the combination as defined in claim 13, the limiting meansincluding a bar at least one surface of which extends angularly to itsaxis, said bar being secured against movement with respect to one ofsaid means and slidable with respect to the other and a stop elementmounted by the bar and engageable with said other means.

15. A mechanism to be attached to and control the dosage dispensed by asyringe assembly which includes a barrel and a plunger reciprocal withinsaid barrel, said mechanism embracing in combination a mounting to beapplied to the barrel of the assembly, a support for association withthe outer end of the plunger forming a part of that assembly, aresilient means extending between and connected to said support andmounting to urge the same in opposite directions away from each other,and stop means also extending between and connected to said support andmounting for limiting the separative movements of the same.

16. In a mechanism as specified in claim 15, and said resilient meansincluding a pair of bowed spring strips at substantially diametricallyopposite points in said mechanism.

17. In a mechanism as specified in claim 15, said support comprising amember to receive the outer end of the plunger and said resilient meansmounting said support in a position such that it is initiallynon-aligned with the bore of said barrel.

18. In a mechanism as specified in claim 15, said stop means including arod slidably engaging said mounting and a stop element adjustablymounted on said rod.

19. In a mechanism as defined in claim 18, said rod being flared in adirection away from said mounting, said stop element being slidablysupported by said rod and contactable with said mounting and clampingmeans carried by said element to engage said rod.

20. A syringe assembly including in combination a barrel having an openrear end, a plunger reciprocal within the bore of said barrel andextending beyond its end, an actuating portion at the outer end of saidplunger, a mounting supported by said barrel and ex tending exteriorlythereof, supporting means connected to the actuating portion of saidplunger, a spring embracing a strip outwardly bowed with respect to saidplunger and means for connecting the opposite ends of said strip to saidmounting and supporting means respectively.

21. For use with a syringe assembly, in combination a mounting member tobe supported by the barrel of such an assembly, a supporting member forengagement with the actuating portion at the outer end of the plunger ofsaid assembly, a bar at least one face of which extends at an inclinewith respect to its: axis to provide a Wedge-shaped body, means forconnecting said bar for movement with one of said members, a stopelement slidably mounted by said bar and engageable with the othermember and adjustable means carried by said stop element and projectableinto the inclined face of said bar to limit movement of said memberswith respect to each other at elected points.

References Cited in the file of this patent UNITED STATES PATENTS2,309,502 Douglas Jan. 26, 1943 2,705,494 Broadwin Apr. 5, 19552,739,590 Yochem Mar. 27, 1956 2,823,674 Yochem Feb. 18, 1958

